Radio receiving system



Feb. 13, 1934. A, H HQTQPP, JR 1,946,582

- RADIO RECEIVING SYSTEM Filed Feb. 10, 1932 RE R U k 4/ 7 5 WIQED RADIO FILTER SYSTEM DETECTOR INVENTOR Alirfifl H. Hutupp, III".

I BY w W ATTORNEY which are fed into a demodulation device.

Patented Feb. 13, 1934 UNITED STATES RADIO RECEIVING SYSTEM Alfred H. Hotopp; Jr.,

to Wired Radio, Inc., poration of Delaware Caldwell, N. J., assignor New York, N. Y., a cor- Application February 10, 1932. Serial No. 591,996

2 Claims.

My invention pertains in general to radio receiving systems and specifically relates to a radio receiving system for receiving wired radio and space radio receiving signals.

In the system of wired radio broadcasting. it is customary to employfrequencies which are of an order considerably lower than those employed in space radio broadcasting. Since space radio receiving apparatus is designed to handle frequencies much higher than those employed for wired radio purposes it is obvious that the usual space radio receiving apparatus cannot be efficiently used for receiving both wired radio and space radio. signals.

One of the objects of my invention consists in providing a system for the reception of wired radio or space radio signals in which the frequency of the wired radio signals is augmented for reception over apparatus designed to handle frequencies common to space radio broadcasting.

A further object consists in producing a com. bined wired radio and space radio receiving system in which a local oscillator generates oscillations of a frequency to which space radio receiving equipment is responsive.

A further object consists in producing a method of receiving wired radio or space radio signals in which wired radio signals are demodulated and then utilizedto, modulate locally generated oscillations of 'a frequency to which space radio equipment is responsive.

I accomplish the above desirable objects in a novel radio receiving system having a space radio receiver, a wired radio receiver, and a source of local oscillations.

In the drawing I have diagrammatically represented one embodiment of the radio receiving organization of my inventign.

My invention contemplates providing means for eifecting the reception of wired radio or space radio program signals on a space radio receiver In my invention, a wired radio filter system is coupled to wire lines carrying current frequency energy for deriving carrier frequency programs The demodulation device supplies program currents at audio frequencies which serve to modulate locally generated oscillations of a frequency suit-- able for reception over the space radio receiver, These modulated oscillations are fed into the input of the space radio receiver and received in a normal manner as if the signals were transmitted through space. By the use of the system of my invention it is, therefore, unnecessary to-alter the circuits of a space radio receiver to provide universal reception inasmuch as the auxiliary apparatus, provided according to my system, supplies signals at frequencies suitable for reception on the space radio receiver.

In this specification I employ the term radio frequency as denoting frequencies commonly employed in space radio broadcasting, while the term carrier frequency is employed as meaning superaudible frequencies suitable for transmission over wire lines and which are considerably lower than those employed for space radio broadcasting.

Referring to the drawing in detail, a wired radio filter system 1 is connected through coupling condensers 2 to power lines 3 which carry program modulated carrier frequency energy. The. filter system 1 comprises a series of inductively coupled meshes for reception of selected carrier frequency programs. Such a selective filter system is described in more detail in a co-pending application of Robert D. Duncan, Jr., Serial Number 495,823, filed November 15, 1930, and entitled -Filter systems. The output of filter system 1 is directed to a detector 4 which includes a space discharge tube 5 and grid leak and condenser 6. The anode circuit of the space discharge tube 5 includes a source of anode voltage '7 and an audio frequency choke coil 8 connected in series therewith which provides a direct current circuit path to the anode.

The anode of the space discharge tube 5 is connected through a radio frequency choke coil 16 to they anode circuit ofspace discharge tube 9 of a modulator and oscillator 10. The modulator and oscillator 10 comprises conventional means for producing sustained high frequency oscillations which are modulated in accordance with audio frequency currents. The anode circuit of space discharge tube 9 includes an inductance 11 and capacitance 34 forming a resonant circuit which is capacitively coupled to a resonant input circuit including an inductance 13 and capacitance 14. According to my invention the modulator and oscillator 10 produces sustained oscillations of a frequency suitable for reception over radio frequency circuits. The audio frequency output of the detector 4 modulates these high frequency oscillations which are picked up by the inductance 15 from inductance 11. The inductance 15 is connected to another inductance 33 which is electromagnetically coupled to an inductance 17 in a space radio receiver 18. The inductance 1'7 is electromagnetically coupled to another inductance 19 which is in series with an antenna. 20 and ground 21. forming a space radio energy collecting system. A switch '12 is connected in series with the inductance 15 and a switch 36 is provided in series with the antenna 20.

A variable condenser 22 is connected in parallel with the inductance 17 and forms a resonant circuit for supplying input energy to the space discharge radio frequency amplifier tube 23. The output of space discharge tube 23 is directed through radio frequency transformer 24 to another space discharge radio frequency amplifier tube 25. The output of space discharge tube 25 is directed through a radio frequency transformer 26 to the input circuit of a space discharge detector tube 27 including the grid leak and condenser 28. The output of the space discharge,

detector tube 27 is directed through an audio frequency transformer 29 to the input of the space discharge audio frequency amplifier tube 30 which has an output circuit including the audio frequency transformer 31 and the loud speaker 32. Suitable sources of operating voltage are providedas shown, in a conventional manner.

The operation of my system for reception of space radio or wired radio program signals is as follows:

For reception of space radio signals, the switch 36 is closed whereby the space radio receiver 18 functions in a normal manner for reception of signals. The program modulated space radio frequency energy is received over the space radio energy collecting system and is amplified at radio frequencies over the space discharge amplifier tubes 23 and 25 and is demodulated by the space discharge detector tube 27. The output of the space discharge detector tube 27 is amplified by the space discharge amplifier tube30 for controlling the loud speaker 32 to audibly reproduce space radio programs.

For the reception of wiredradio signals from p the power lines 3, the switch 12 is closed and the operation of the detector 4 and modulator and 0scillator 10 is initiated. The program modulated carrier frequency energy derived from the power lines 3 by the filter system 1 is demodulated by space discharge tube 5 of detector 4. The audio frequency output of detector 5 is directed to the modulator and oscillator 10 whereby modulated radio frequency oscillations are induced in the inductance 17 from inductance 33. These program modulated high frequency oscillations are of a frequency similar to the radio frequencies normally received over the antenna 20 and are therefore amplified at radio frequencies in a normal manner by the space discharge amplifier tubes 23 and 25. The detector tube 27 then functions in the usual manner, as before described, to effect demodulation of the high frequency currents whereby the audio frequency amplifier tube 30 controls the translating device 32 for audible reproduction of the wired radio programs.

It will now be evident that I have provided a novel radio receiving system in which a space radio receiver is provided with auxiliary means for *the reception of wired radio signals at space radio frequencies. Although I have shown a preferred embodiment of my invention I do not desire to be limited thereto except insofar as may be pointed out in the appended claims.

What I claim as new and original and desire to secure by Letters Patent of the United States is:

' 1. A radio receiving system comprising, a space radio energy collecting system, a radio frequency amplifier, a wired radio filter system connected to wire lines conveying modulated carrier frequency energy, a demodulating device connected to the output of said filter system for demodulating said carrier frequency energy, a radio frequency oscillator, connections from said demodulating device to said oscillator for causing the output energy of said demodulating device to modulate the radio frequency oscillations produced by said oscillator,said connections including a 'radio frequency choke coil to prevent energy feed-back from said oscillator to said demodulating device, and connections from the output of said oscillator to the input of said radio frequency amplifier.

2. A radio receiving system comprising, wire lines for conveying modulated carrier frequency energy, a detector for demodulating said carrier frequency energy to produce audio frequency current, a space radio energy collecting system, a space radio receiving organization connected thereto, a local oscillator for producing oscillations of a frequency suitable for reception by said space radio receiving organization, connections from said detector to said oscillator whereby said oscillations are modulated by said audio frequency currents from said detector, said connections including an audio frequency choke coil to ensure that substantially all of said audio frequency'currents are transmitted from said detector to said local oscillator and a radio frequency choke coil to prevent energy feed-back from said oscillator to said detector, and connections for feeding said modulated oscillations to said space 

